1. Field of the Invention
This invention generally relates to a one-way clutch assembly to be interposed between a pair of outer and inner rings to control the transmission of a rotating torque therebetween only in a predetermined one rotating direction, and, in particular, to a retainer plate which is to be fixedly attached to either one or both of the inner and outer rings for retaining such a one-way clutch assembly in position between the inner and outer rings axially.
2. Description of the Prior Art
A one-way, clutch assembly for use in a driving apparatus, such as a prime mover, for controlling the transmission of a rotating force between a pair of rotating objects, such as a pair of outer and inner rings, such that a rotating force is transmitted only in a predetermined rotating direction between the two objects is well known. Such a one-way clutch assembly may, for example, include a so-called sprag-synchronized one-way clutch assembly. FIG. 9 schematically illustrates a typical prior art structure in which a one-way clutch assembly is mounted in position using a prior art retainer plate. As shown, a one-way clutch assembly 1 is disposed between an outer ring 3 and an inner ring 4 and the one-way clutch assembly 1 is set in position by a pair of retainer plates 2 which are fixedly attached to the outer ring 3 on opposite sides. Since the one-way clutch assembly 1 is sandwiched between the pair of retainer plates 2 which are fixedly attached to the opposite sides of the outer ring 3, the one-way clutch assembly 1 is maintained in position axially.
Disposed in contact with the pair of retainer plates 2 in the axial direction is a pair of thrust bearings 8a and 8b, which are mounted between another stationary object and the outer ring 3 with the retainer plates 2 sandwiched between the outer ring 3 and the thrust bearings 8a, 8b. In this manner, the one-way clutch assembly 1 may be securely maintained in position axially. If the magnitude of the load in the thrust direction is not so significant, use is often made of a spacer comprised of a resin material, which also serves as a thrust bearing, in place of a typical thrust bearing. A clutch plate assembly 5 is mounted at the outer peripheral surface of the outer ring 3. A plurality of through holes 7 are provided at the outer peripheral surface of the outer ring 3 so as to allow a lubricant, such as oil, to be supplied to the clutch plate assembly 5. On the other hand, a supply port 6 is formed in the inner ring 4 so as to supply the lubricant from a source of lubricant to the one-way clutch assembly 1.
In the above-described typical prior art structure, if the thrust bearings 8a and 8b are comprised of a sliding contact type thrust bearings, such as spacer thrust bearings, the thrust bearings 8a and 8b are brought into surface contact with the retainer plates 2. And, thus, when the lubricant supplied from a source through the supply port 6, it is splashed against the thrust bearings 8a and 8b due to centrifugal forces; however, the lubricant thus supplied is blocked by the bearings 8a and 8b since they are in surface contact with the respective retainer plates 2. If the lubricant is not supplied sufficiently to the sliding contacts of the thrust bearings 8a and 8b, heat is produced in the thrust bearings 8a and 8b significantly and they may be damaged or malfunction. In the prior art structure shown in FIG. 9, since the thrust bearings 8a and 8b are in surface contact with the respective retainer plates 2, the lubricant supplied through the supply port 6 is not sufficiently and continuously supplied into the sliding contacts of the thrust bearings 8a and 8b.